Asymptomatic siblings, age 26-59, of patients with coronary artery disease events under age 60 underwent risk-factor screening and testing for occult coronary artery disease (exercise thallium imaging). Risk- factor screening included measurement of blood pressure, fasting lipid profile, blood sugar, serum insulin, apolipoprotein B and A1, lipoprotein (a), fibrinogen, spontaneous and ADP-induced platelet aggregation, platelet-activated IIb/IIIa receptor density, serum thromboxane B2, echocardiogram for left-ventricular mass and function, carotid ultrasound, smoking history, resting and signal-averaged electrocardiogram, maximal treadmill exercise test with thallium tomography, pre and post-exercise arm/leg blood pressure measurements, Holter monitor for silent ischemia, arrhythmias, and heart rate variability, and changes in blood pressure and heart during the cold pressor and Stroop color word tests. Approximately 32% of the individuals screened have been current smokers, 40% had LDL cholesterol greater or less than 160mg/dl, 29% had HDL cholesterol less or equal to 40mg/dl, and about 37% of screenees had hypertension with systolic blood pressure equal to or greater than 140mmHg or diastolic blood pressure greater than or equal to 90mmHg, and 6% had diabetes. Eleven percent of the group have had an abnormal exercise thallium scan, and 8% an abnormal exercise electrocardiogram. Only 20% of individuals did not have any of the traditional coronary risk factors. In addition to the initial screening studies, we also performed two-year follow-up risk factor measurements on 44 siblings (16 African Americans, 28 whites), to determine actual changes in risk factor levels resulting from the randomization of these individuals into a nurse practitioner- directed multiple risk factor intervention program and a "usual care" treatment arm. The results of these two approaches have been compared to determine the value of the nurse-directed intensive risk factor modification efforts. The nurse intervention group significantly lowered LDL-cholesterol and decreased dietary fat, whereas the usual care group did not show any significant changes between baseline and 1 and 2-year follow-ups. Declines were seen in blood pressure and smoking in the nurse group, and more participants were taking and adhering to standard pharmacotherapy. At baseline, 24% of both the nurse and usual care groups had abnormal exercise tests and/or thallium scans. At 2 years, this number reduced to 12% in the nurse group. Results to date indicate that African-American siblings have higher prevalences of hypertension (46% vs 53%), lp(a) equal to or greater than 25mg/dl (75% vs 40%), diabetes (12% vs 4%), and serum insulin greater than 20uU/ml(21% vs 13%), and lower prevalences of HDL-cholesterol less than or equal to 40mg/dl (21% vs 32%) and triglycerides equal to or greater than 200mg/dl(10% vs 25%). The prevalences of current smoking, LDL-cholesterol equal to or greater than 160mg/dl, and abnormal exercise tests and/or thallium scan have been similar.